Variable Sensitivity-Based Deterministic Robust Design for Nonlinear System

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
XinJiang Lu ◽  
Han-Xiong Li ◽  
C. L. Philip Chen
Keyword(s):  
Nonlinear System ◽  
Robust Design ◽  
Nonlinear Effect ◽  
Nonlinear Term ◽  
Design Method ◽  
Design Approach ◽  
Sensitivity Matrix ◽  
Variable Sensitivity ◽  
Sensitivity Approach ◽  
Variation Simulation

In this paper, a novel robust design approach is proposed to design the robustness of the nonlinear system under large uncontrollable variation. First, a variable sensitivity approach is proposed to formulate the nonlinear effect into the variable sensitivity matrix. Then, a variable sensitivity-based robust design is developed to minimize the variable sensitivity matrix so that the influence of the uncontrollable variation to the performance will be minimized. Since the proposed robust design considers the influence of the nonlinear term in a large design region, it can effectively improve the robustness of the nonlinear system despite large uncontrollable variation. Simulation examples have demonstrated the effectiveness of the proposed design method.

Reliability-Based Robust Design for Mechanical Components under Small-Sample Information

2012 ◽  
Vol 215-216 ◽  
pp. 804-807
Author(s):  
Xiang Dong He ◽  
Jia Peng Chu
Keyword(s):  
Robust Design ◽  
Design Method ◽  
Small Sample ◽  
Design Approach ◽  
High Confidence ◽  
Mechanical Parts ◽  
Estimate Reliability ◽  
Practical Engineering ◽  
Definition Of ◽  
Robust Design Method

In engineering design, according to not considering past experience information; hence, to make structure parameters for achieving high confidence level, much data for traditional reliability-based robust design must be adequately collected, analyzed, and tested. However, in practical engineering, it is very difficult for doing much test, only for getting in the form of finite test samples. Under the conditions, it has much difficult for the traditional reliability-based robust design. In the article, we present a new reliability-based robust design method that solves the form of incomplete information. The method adopts a Bayesian inference technique to estimate reliability, gives definition of Bayesian reliability. In the research, the mechanical parts bayesian reliability-based robust design mathematical model is established and the bayesian reliability-based robust design approach is presented. The numerical results illustrates the method presented is an efficient and practical reliability-based robust design approach.

Stability Based Robust Eigenvalue Design for Tolerance

2009 ◽  
Vol 131 (8) ◽  
Author(s):  
XinJiang Lu ◽  
Han-Xiong Li
Keyword(s):  
Robust Design ◽  
Design Method ◽  
Integrated Approach ◽  
System Stability ◽  
Design Parameters ◽  
Complex Eigenvalue ◽  
Sensitivity Matrix ◽  
Eigenvalue Sensitivity ◽  
Design Systems ◽  
Robust Design Method

A novel integrated approach is developed to design systems for stability and robustness. First, design parameters with large variation bounds are chosen to maintain system stability. Then, a robust eigenvalue design problem is considered to make the dynamic response less sensitive to parameter variations. A new complex sensitivity matrix is derived from the system dynamics with the eigenvalue variation approximated into a first-order model by means of the eigenvector orthogonal theory. Through a proper transformation, the complex eigenvalue sensitivity of the Jacobian matrix can still be processed by the traditional robust design approach. By minimizing the eigenvalue sensitivity, design parameters can be obtained for stability as well as robustness. Furthermore, the tolerance space of the selected parameters can be maximized to improve robust performance. A Laval rotor example is used to demonstrate the effectiveness of the proposed robust design method.

scholarly journals Axiomatic Design Approach for Nonlinear Multiple Objective Optimizaton Problem and Robustness in Spring Design

2017 ◽  
Vol 17 (1) ◽  
pp. 63-71
Author(s):  
Ahmet Feyzioglu ◽  
A. Kerim Kar
Keyword(s):  
Robust Design ◽  
Design Method ◽  
Minimum Cost ◽  
Axiomatic Design ◽  
General Information ◽  
Design Approach ◽  
Design Stage ◽  
Independence Axiom ◽  
Multi Objective ◽  
Parameter Values

Abstract This paper gives general information about multi-objective, axiomatic and robust design approaches and considersasolution model of nonlinear multi-objective optimization problem based on applyinganew robust design approach. Both axiomatic and robust design approaches were used complementarily inacase study with distinct multi-objectives. In this case study, the main target was achieving each objective optimum to minimize the mass and the shear stress ofaspring by integrating robustness and durability at the design stage due to trade off between objectives. This spring problem was examined using the independence axiom of the axiomatic design methodology. Also, semangularity and reangularity concepts were used and design matrices were formed to find coupled and decoupled solutions. It was observed that there were some acceptable design parameter values for which the design became decoupled. Graphical and numerical results were checked to see if they were compatible with each other. Finally, this decoupled design was given appropriate tolerances by using robust design method. This way,arobust and durable spring was designed which would satisfy the given specifications with minimum cost in the existing literature from the view point of axiomatic design approach.

Model-Based Probabilistic Robust Design With Data-Based Uncertainty Compensation for Partially Unknown System

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
XinJiang Lu ◽  
Han-Xiong Li ◽  
C. L. Philip Chen
Keyword(s):  
Robust Design ◽  
Model Uncertainty ◽  
Linear Structure ◽  
Parameter Variation ◽  
Design Approach ◽  
Design Stage ◽  
Process Data ◽  
Sensitivity Matrix ◽  
Model Based ◽  
Uncertainty Compensation

Model uncertainty often results from incomplete system knowledge or simplification made at the design stage. In this paper, a hybrid model/data-based probabilistic design approach is proposed to design a nonlinear system to be robust under the circumstances of parameter variation and model uncertainty. First, the system is formulated under a linear structure which will serve as a nominal model of the system. All model uncertainties and nonlinearities will be placed under a sensitivity matrix with its bound estimated from process data. On this basis, a model-based robust design method is developed to minimize the influence of parameter variation in relation to performance covariance. Since this proposed design approach possesses both merits from the model-based robust design as well as from the data-based uncertainty compensation, it can effectively achieve robustness for partially unknown nonlinear systems. Finally, two practical examples demonstrate and confirm the effectiveness of the proposed method.

A Robust Design Perspective on Factors Influencing Geometric Quality in Metal Additive Manufacturing

2020 ◽  
pp. 1-35
Author(s):  
Vaishak Ramesh Sagar ◽  
Samuel Lorin ◽  
Kristina Wärmefjord ◽  
Rikard Söderberg
Keyword(s):  
Additive Manufacturing ◽  
Robust Design ◽  
Design Method ◽  
Robustness Analysis ◽  
Geometric Quality ◽  
Geometric Robustness ◽  
Robust Design Method ◽  
Geometric Variation ◽  
Variation Simulation

Abstract Additive manufacturing (AM) for metals is a widely researched, continuously enhanced manufacturing process and is implemented across various industries. However, the AM process exhibits variation that affects the geometric quality of the end product. The effect of process variation on geometric quality is rarely considered during design stages. This paper discusses the various sources that contribute to geometric variation and the prospect of applying robust design method to produce geometry assured AM products. A framework for geometric robustness analysis of AM products is presented as an outcome. This framework would facilitate development of methods and tools to produce geometry assured AM products. The prospects of variation simulation to support geometric robustness analysis and the challenges associated with it are discussed.

scholarly journals Novel Robust Design Method of Multilayer Optical Coatings

ISRN Optics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Suyong Wu ◽  
Xingwu Long ◽  
Kaiyong Yang
Keyword(s):  
Robust Design ◽  
Optimization Design ◽  
Design Method ◽  
Analytical Calculation ◽  
Design Procedure ◽  
Deposition Process ◽  
Practical Significance ◽  
Optical Coatings ◽  
Optical Films ◽  
Robust Design Method

We present a novel fast robust design method of multilayer optical coatings. The sensitivity of optical films to production errors is controlled in the whole optimization design procedure. We derive an analytical calculation model for fast robust design of multilayer optical coatings. We demonstrate its effectiveness by successful application of the robust design method to a neutral beam splitter. It is showed that the novel robust design method owns an inherent fast computation characteristic and the designed film is insensitive to the monitoring thickness errors in deposition process. This method is especially of practical significance to improve the mass production yields and repetitive production of high-quality optical coatings.

A time-varying reliability-based robust design method considering overall efficiency of axial piston pump

2021 ◽  
pp. 1748006X2110661
Author(s):  
Zunling Du ◽  
Yimin Zhang
Keyword(s):  
Energy Conversion ◽  
Robust Design ◽  
Design Method ◽  
Design Stage ◽  
Structure Parameters ◽  
Time Varying ◽  
Design Variables ◽  
Reliability Method ◽  
Overall Efficiency ◽  
Axial Piston

Axial piston pumps (APPs) are the core energy conversion components in a hydraulic transmission system. Energy conversion efficiency is critically important for the performance and energy-saving of the pumps. In this paper, a time-varying reliability design method for the overall efficiency of APPs was established. The theoretical and practical instantaneous torque and flow rate of the whole APP were derived through comprehensive analysis of a single piston-slipper group. Moreover, as a case study, the developed model for the instantaneous overall efficiency was verified with a PPV103-10 pump from HYDAC. The time-variation of reliability for the pump was revealed by a fourth-order moment technique considering the randomness of working conditions and structure parameters, and the proposed reliability method was validated by Monte Carlo simulation. The effects of the mean values and variance sensitivity of random variables on the overall efficiency reliability were analyzed. Furthermore, the optimized time point and design variables were selected. The optimal structure parameters were obtained to meet the reliability requirement and the sensitivity of design variables was significantly reduced through the reliability-based robust design. The proposed method provides a theoretical basis for designers to improve the overall efficiency of APPs in the design stage.

AN OPTIMIZATION MODEL FOR PRELIMINARY STABILITY AND CONFIGURATION ANALYSES OF SEMI-SUBMERSIBLES

2021 ◽  
Vol 159 (A3) ◽  
Author(s):  
G D Gosain ◽  
R Sharma ◽  
Tae-wan Kim
Keyword(s):  
Optimization Model ◽  
Design Method ◽  
Optimization Techniques ◽  
Design Approach ◽  
Preliminary Design ◽  
Design Environment ◽  
Preliminary Stage ◽  
Steel Weight ◽  
Motion Characteristics ◽  
Almost All

In the modern era of design governed by economics and efficiency, the preliminary design of a semi-submersible is critically important because in an evolutionary design environment new designs evolve from the basic preliminary designs and the basic dimensions and configurations affect almost all the parameters related to the economics and efficiency (e.g. hydrodynamic response, stability, deck load and structural steel weight of the structure, etc.). The present paper is focused on exploring an optimum design method that aims not only at optimum motion characteristics but also optimum stability, manufacturing and operational efficiency. Our proposed method determines the most preferable optimum principal dimensions of a semi-submersible that satisfies the desired requirements for motion performance and stability at the preliminary stage of design. Our proposed design approach interlinks the mathematical design model with the global optimization techniques and this paper presents the preliminary design approach, the mathematical model of optimization. Finally, a real world design example of a semi-submersible is presented to show the applicability and efficiency of the proposed design optimization model at the preliminary stage of design.

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